Polyphase-electromagnet brake control.



B. MCINNERNEY.

POLYPHASE ELECTRONIAGNET BRAKE CONTROL. APPLICATION msu 1uLY1a.1914.RENEW@ APR. 2`1, 1917.

bggg @D I Paimed Aug. 28, NW.

UNITED sTATEs PATENT on BENJAMIN MCIN'NERNEY, OF COUNCIL `IBLUFFS, IOWA,.ASSIGNOR TO WESTINGHOUSE ELECTRIC AND MANUFACTURING COMPANY, -OE' EASTPITTSBURGH, ENISI'SYL- VANIA, A CORPORATION OF .PENNSYLVANIA.

POLYPHASE-ELECTROMAGNET BRAKE CONTROL.

Specification of Letters Patent.

Application ledlJ'uly 18, 1914, Serial No. 851,750. Renewed April 21,1917. Serial No. 163,79.

lb /JZZ whom it may concern: v

Be it known that I, BENJAMIN MCINNER- NEY, a citizen of the UnitedStates, residing at'Council Bluffs, in the county of Pottawattamie,State of Iowa, have invented a new' and useful Improvement inPolyphase-Electroniagnet Brake Controls, of which the following .is aspecification,

My invention relates to improvements in electromagnetic means foreffecting the release of dynamically actuated brakes such as areemployed for retarding the motion of elevators, hoists and othermachines.

One object of my invention is to provide a polyphase alternating currentelectromagnet which does not chatter and is free from the humming ofother objectionable noises that usually characterize magnets of thistype.

A second object of my invention is to provide an alternating currentmagnet having an armature that is positively pivoted and is firmlyseated in the same position relatively to the pole pieces in successiveoperations.

Another object of my invention is to provide an clectromagnet having anarmature that is provided Witha short lever arm and is of small Weightin order that the movement necessary to operate the brake may be smalland the resulting impact shall be substantially eliminated.

A further object of my invention is to l provide an electromagnet ofsimplified construction Which operates in connection with a mechanismthat is subject tov very slight wear and the efficiency of which is notdecreased by such Wear of its parts.

A serious disadvantage in connection With the operation of magnet brakesis thetendency for the armature to get out of adjustment because of Wearof its bearing parts. In such cases, the armature does not seat properlybecause the plane'of its face is out of alinement With the faces of thepole pieces. This condition arises in many cases from the manner inwhich the armature is pivoted. When the latter is pivoted near itscentral portion, it is obvious that a very Vslight wear of the bearingparts permits a relatively large lateral movement of the end portions ofthe armature, thus aliewing the latter to twist ont of alinement withthe faces of the pole pieces..

The above described construction renders it substantially impossible tosecure noiseless operation for any considerable period, thereby mentsnecessary to prevent undue vibrations. Another cause of chattering' andvibration Patented Ang. 28, i917.

rendering very frequent adjust-- is'the arrangement or' the pole piecesin the i same plane. In case one or both of the outer pole piecesbecomes slightly shorter tl a the others, the tendency to vibrate isgreatly increased, as ivill be readily understood.

According to my invention, the armature is pivotally mounted at vitsextreme end portions. The pivotal axis is arranged parallel to the planeof the faces of the coacting pole pieces and parallel to the alinementof the pole pieces. By means of this arrangement, it will be obviousthat a slight Wear ci the bearing` parts will not permit the armature tomove out of alinement with the pole lfaces of the pole pieces. Such aconditicn will arise only when there is a substantial d" ference in theamount of Wear the respective end portions of the armature.

The clectromag'net is provied with plurality of pole pieces, the cutwhich are-slightly longer than mediate pole pieces which are si icuii bythe energizing' -coils. This constrr insures that the armature will beparts which engage its end portion; one of the intermediate pole niecescannet serve as a fulcrum to produce a rockingY inction. In such anarrangement, lthe magnetic force of the pole pieces is always exerted ata point between the pole pieces which snpport the armature.

The details of my invention will be scribed in connection withtheaccompanying drawings in which Figure l is an end view, in elevation,of'a mechanism constructed in accordance with my invention, theelectrical circuits being shown diagrammatically. Fig. 2 is adiagrammatic .view of the polyphase electromagnet. Fig. Sis' a sideview, in elevation, of the mechanism of Fig. i, the diagram of theelectrical connections being oinitted.

A brake m may be a cy tating part or drinn or" a' ISU tion of which isto be controlled by a brake. As illustrated. the wheel m is in the formeustomarilv employed in connection with elevators.- but it will heunderstood that it may represent'ihe corresponding part of anyelectrically controlled machine. Two brake shoes s and s. which arepivotally mounted at the respective sides of the wheel m, are normallycaused to frictionally engage the periphery4 of the wheel by a springthat is mounted upon an adjusting,r bolt y.

An electromagnet comprises a body member 71 ha ringr outer pole pieces eand e and internualiaie pole pieces f] and al which respectivelyconstitute core members for coils c and r". The pole pieces c and e areslie'l'itly longer than the pole pieces fl and d so thatithe plane ofthe faces ofthe former is slightly above the plane of the faces of thelatter. The electromagnet also comprises an armature member u whichisconnected, at its end portions, to levers z' and z". The levers i and iare pirotally mounted at 79 and [/,Eind points 7) and p are so arrangedthat the pivotal axis of the armature is parallel to the plane of thefaces of the pole pieces e and e. \Vhen the coils are energized,.thearn'iature is seated upon the faces ol the pole pieces e and e.

One end of the armature member (L is connected to the brake shoe s bythe lever i, a. link a bell-crank lever 7c and an eye bolt Z. The otherend of the armature is connected to the brake shoe fr by a similarmechanism i, y", la and Z. The pivotal axis of the armature u. throughthe points) and 72 is so arrane'ed that-the shortest possible move# mentof the armature operates through the lever mechanism above described toeffect the disengagement of the brake shoes. The eye bolts 7 and Z areprovided with adjusting nuts for varyin;r lthe positions of the bra kcshoes relatively to the armature.

As indicated diagrammatically in Fig. 1, the coils c and c are suppliedWith current from a three-phase source. The coil c is connected to lineconductors 1 and 2 by conductors' l() and E20y reslfiectively. The coilc is similarly connected to line conductors 2 and i3 by conductors Q1and 30, respectively. lVhile this system of connections is shown by wa yof example, it is the preferred manner in which current is supplied forenergizingr the coils c and c. It is well known that the total powerdelivered to such a circuit is always `greater than zero and that atleast one ot' the coils c and c is always energized to some degree. Ttwill be evident, therefore. that a pull will be exerted on the armaturemen'iber fr, by one or both 0f the pole pieces n and c as lona as thecoils are in eireuil. A pull will also be exerted substantiallycontinuously by each of the pole pieces 7. and d.

The mmol-tant advantage of such an arrangement lies in the fart that aconstant pull is exerted on the armature between its points of supportand there is no periodin which the armature is loosely held againsteither of the pole pieces. 'lhis feature, together with the manner ofpivotally mountingethe armature so as to prevent any twisting' motion,insures that the aru'iature will always be firmly seated upon thecoacting pole pieces.

rlhe operation of the mechanism will be readily understood. lVhen theline conductors 1, L) and 3 are connected to any suitable source` (notshown).y the coils c and c will be energized and the arniature a will bedrawn downwardly by the magrnetic force of the poles and al and c andc". Since the plane of the armature is parallel to that of the faces ofthe pole pieces c and e', the armature will be. firmly 'seated upon thepole pieces and retained in that position while, the coils areenergized, rilhe downward movement of the armature a operates throughthe lever mechanisms to separate the brake shoes v and s against theforce of the spring' and thereby release the wheel m.

When the magnet is deenergized by opening` the. circuits of the coils cand c', the spring fn operates to effect the engagement of the brakeshoes s and with the Wheel m and thus bring the motor or other machinewith which it may be connected quickly and safely to rest.

An arrangement in which the coils e and c are connected to a two-phasesource is shown diagrammatically in Fig. 2. The coil c is connected toline conductors 1 and 2 by means of conductors 10 and 20, respectively,and the coil c is similarly connected to line conductors 3 and 4 bymeans of conductors 30 and 40, respectively. It is understood, however,that the arrangements of the circuits for the coils c and o are shown byway of example only and that l do not wish to limit myself to either ofthe arrangements shown and described.

The advantages of my invention will be apparent to those skilled in theart to which my invention appertains. The mechanism is composed of fewand simple parts. The armature is positively pivoted in such a mannerthat a slight wear of the hearing parts cannot affect its quietoperation. 4A convenient means is provided for making such adjustmentsas may be necessary in order that the several moving parts may havetheir proper relation. The magnet 0perates through a vvery shortdistance to effeet the engagement and disengagen'ient of the brake shoesand maintains its operative position substantially without noise andwiti'iout chattering. Y

lVhat 1. claim and desire to secure hy Letters Patent is:

1. 1n a brake, the comhin-.dion with a brake shoeA` ot a magnet havinfbTa plurality .ture connected to xsaid brake shoe for coacting n ith saidoutermost pole pieces.

2. ln a brake, the wmbiinltion with an armature which is pivotallysupported at its end portions, and a pair ot brake shoes respectivelyconnected to said end portions7 of means l'or exerting a` substantially0011-' stant pull upon sairl arnnllure between its points' ot' support.

ln a brake, theI emnbination with a pair of brake shoes, ot' a magnethaving` a pluralit'v of pole pieces. an armature pivotally supported atits ends and adapted to seat upon at least two ot lsaid pole pieces, andmeans 'for ailjustably eonneriug each einl o't` saifl armature to oneol. saill brake shoes.

fl. lira brake. the Combination with a brake shoe. ot' a magnet havlngla plurality ot' alimal pole pieces, the outermost ol which projectbe'vonrl the plane of the others', and an armature connected to saidbrake shoe an l having a pivotal axis substantiall)r parallel to theplane oi tlieflaees oi' tho outermost pole pieces.

ln a brake, the, eonlhinatimi with a laalto shoe, of a magnet having aplurality7 oi' alined pole pieces. the outermost ol which project beyondthe planeI ot the others, and an armature, connor-,tml to said bralteshoe anrl havingT a pivotal axis suhstantiall)Y parallel to thealinement of said pole pieces, said armature being adapted to seat uponthe, outermost pole pieces.

5. In a brake, the etanbination with :1- hralie shoe, of a magnet havinga plurality of alined pole pieces, the outermost of which project beyondthe plane of the faces ot' the others, coils upon intermediate polepieces, and a pivotally mounted armature connectell to said brake shoefor eoacting with the outermost 'pole pieces.

7. ln a brake, the combination with a brake shoe, of a magnet having' aplurality ot alined pole pieces, the outermost of which project bevondthe plano of the faces of the others, coils upon intermediate poleIpiel-es, alnl an armature connected to said brake shoe having a piwlalaxis substantiall \fY parallel to the alim-nient of said pole pieees andadapted to seat upon the onterinost polo pieces.

ln a brake. the combination with an armature which is pivotall'vsupported at its end portions.y and a pair olt brake members connectedto lsaid armature and alinetl with the axis of pivotal support. ol meansfor eX- erting' a substantiall)v constant pull upon sail armaturebetween its points of support.

Wil nesses:

linnn lV. HUGHES, llnxnv Pn'rnnsox.

